package com.demo.interceptor;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.log4j.Logger;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

/**
 * @author: demo
 * @Date: 12-10-24
 * @Time: 下午5:03
 */
public class CommonInterceptor implements HandlerInterceptor {
	
	protected Logger logger= Logger.getLogger(CommonInterceptor.class);


    /**
     * 在业务处理器处理请求之前被调用
     * 如果返回false
     *     从当前的拦截器往回执行所有拦截器的afterCompletion(),再退出拦截器链
     *
     * 如果返回true
     *    执行下一个拦截器,直到所有的拦截器都执行完毕
     *    再执行被拦截的Controller
     *    然后进入拦截器链,
     *    从最后一个拦截器往回执行所有的postHandle()
     *    接着再从最后一个拦截器往回执行所有的afterCompletion()
     */
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object o) throws Exception {
    	logger.info("##############执行顺序: 1、preHandle##############");
        String url=request.getRequestURL().toString();
        if(url.contains("test")){
            request.setAttribute("msg","url = "+url+" 被拦截器"+this.getClass()+"拦截成功!");
            request.getRequestDispatcher("500.jsp").forward(request, response);
            return false;
        }
        System.out.println("url = "+url+" 允许访问!");
        return true;
    }

    /**
     *  在业务处理器处理请求执行完成后,生成视图之前执行的动作
     *
     * @param o
     * @param modelAndView
     * @throws Exception
     */

    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object o, ModelAndView modelAndView) throws Exception {
    	logger.info("##############执行顺序: 2、postHandle##############");
    }

    /**
     * 在DispatcherServlet完全处理完请求后被调用
     *
     *   当有拦截器抛出异常时,会从当前拦截器往回执行所有的拦截器的afterCompletion()
     */
    public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {
    	logger.info("##############执行顺序: 3、afterCompletion##############");
    }
}
